Why You're Coughing After Your Run — and How to Prevent It

why do I cough after I run?: a photo of a woman in exercise clothes bending over and coughing, presumably after running
why do I cough after I run?: a photo of a woman in exercise clothes bending over and coughing, presumably after running

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As a runner, I try to get my workouts in outdoors as much as possible to mimic race-day conditions — and this is despite the fact that I'm a New York City dweller, which means for half the year, it's pretty freaking cold and the air's kinda dirty. (BTW, the air quality at your gym may not be so clear, either.) But whenever I do a really tough run — say, 10-plus miles or a speedy interval session — I come home hacking up a lung.

Despite the fact that the cough doesn't usually persist, it does occur fairly regularly. So I did exactly what any curious info seeker would do: I asked Google, "Why do I cough after I run?" Surprisingly, there weren't many science-based answers out there.

What I did find, though, was a little-known condition dubbed "track hack" or "track cough" to runners, "pursuiter's cough" to cyclists, and even "hike hack" to outdoorsy types. To learn more about this phenomenon of coughing after running and other types of physical activity, I checked in with Raymond Casciari, M.D., a pulmonologist and the chief medical officer of St. Joseph Hospital in Orange, California. He's worked with a slew of Olympic athletes since 1978, and unlike the majority of the Internet, has seen this type of cough before. Here, he breaks down what you need to know about coughing after running and exercise in general.

Why You're Coughing After Running and Exercising

First things first, a primer on what makes your lungs so sensitive in the first place. "There are only three parts of your body that interact with the outside world: your skin, your GI tract, and your lungs. And your lungs have the worst protection of the three," explains Dr. Casciari. "Your lungs are very delicate by nature — they have to exchange oxygen through a thin membrane," he adds. That makes them even more prone to be affected by various conditions, including both your workout and the outside environment.

My cough in particular seems to be affected by both of those conditions, as it comes after long runs, especially when it's cold out or the air's particularly dry. Turns out, both of those situations are what Dr. Casciari refers to as bronchial irritants; therefore, "track hack" is no more than an irritant-based cough. And if you live in an urban area, there are more pollutants in the air — so, more irritants. I'm probably inhaling "benzenes, unburned hydrocarbons, and ozone," all of which contribute to a cough, says Dr. Casciari. Other irritants can include pollen, dust, bacteria, and allergens.

In these situations, your post-run coughs will likely be a phlegmy affair. "Your lungs produce mucous to protect themselves," and it coats your bronchial surfaces, protecting them from factors like cold, dry air, says Dr. Casciari. "It's kind of like if you put Vaseline all over your body if you're a swimmer: It's a layer of protection," he says. Translation: While your track hack will likely be productive (similar to coughs that produce phlegm or mucus and are commonly caused by viral illnesses and infections), it's not a cause for alarm.

What also makes track hack unique is that it's often caused when you stop breathing through your nose (due to the extreme amount of effort you're exerting) and use your mouth instead. Unfortunately, your nose is a far better air filter than your mouth. "When the air hits your lungs, ideally, it's 100 percent humidified and warmed to body temperature since the mucosa of your bronchus are very sensitive to cold, dry air," says Dr. Casciari. "Your nose is a fantastic humidifier and warmer of the air, but when exercising at maximum capacity, I realize it is difficult to (breathe through your nose)," he notes.

What's more, breathing through your mouth alone can actually cause coughing after running, too. "When you're moving large quantities of air through the bronchial mucosa, you're actually cooling them," he says — the exact opposite of the desired effect. (Related: Should You Be Taping Your Mouth Shut for Better Sleep?)

When Coughing After Running Becomes a Concern

Not all post-run or post-workout coughs are caused by exposure to irritants or breathing through your mouth. To pinpoint the driving force behind your hacks, do an overall self-assessment of your current health, recommends Dr. Casciari. Take a look at how you're doing overall, he suggests. For example, if you have a fever, you could be suffering from a respiratory tract infection that's causing coughing after exercise.

Gastroesophageal reflux-induced coughs — when your stomach contents come back up into your esophagus and cause a cough — could also be to blame, says Dr. Casciari. "The way you'd differentiate this from a runner's cough, though, is to notice when the cough occurs," he says. "Runner's cough will always occur after an exposure to running, whereas a cough from GERD [gastroesophageal reflux disease] could be anytime: in the middle of the night, watching a movie, but also during and after running, too," he explains.

Another important condition to rule out is exercise-induced asthma, which is different and more serious than the typical runner's cough. Exercise-induced asthma, unlike track hack, is a prolonged condition that lasts far beyond the five or 10 minutes that follow a hard workout. Not only will the cough continue, but you'll also wheeze — something that generally won't happen with track hack — and experience overall decreased performance.

Unlike a simple cough, asthma causes the lungs to repeatedly spasm, constricting and inflaming the airways and ultimately causing decreased airflow. And just because you didn't have asthma as a kid doesn't mean you can't develop it later in life: "Some people are subclinical asthmatics," explains Dr. Casciari. "They never knew they had asthma because the only thing that brings on the asthma is exposure to extreme conditions, including hard exercise," he says.

Since there are a slew of conditions that can cause this type of cough, you'll want to check in with your doctor to eliminate any serious medical concerns — particularly if you're coughing after running or exercising consistently, recommends Dr. Casciari. "Ask yourself, 'Could it be heart disease?' Could you be having an arrhythmia?" he notes. Make sure to carefully eliminate any of these health concerns.

For exercise-induced asthma specifically, a doctor can test for the condition with a tool known as a spirometer, which measures the amount of air you're able to breathe in and out, according to the Mayo Clinic. If you think asthma is behind your coughing after running, see your general practitioner for a test, and meet with a pulmonary specialist or exercise physiologist if your symptoms don't cease, suggests Dr. Casciari.

How to Prevent Coughing After Running

The most important step to preventing coughing after running? Do not grab a bottle of Robitussin. "That will just mask the symptoms of runner's cough," says Dr. Casciari. Instead, try to avoid the irritants. So, for example, if you're running at night, the air is likely more polluted; try running in the morning to see if that changes things. Similarly, if it's the cold temperatures that seem to get you, run indoors instead (and if you're on the treadmill, step the incline up to 1.0 — that will help mimic outdoor conditions, which go up and down, unlike the flat belt).

Another suggestion is to create a cocoon of heat around your mouth to mimic a moist, warm environment and help warm your breath, says Dr. Casciari. Do it yourself with a scarf or buy a cold weather-specific balaclava or neck gaiter to create the cocoon if you still want or need to exercise outdoors, he suggests.

There's also research that suggests that drinking or ingesting caffeine prior to a workout can help reduce your risk of experiencing post-workout track hack and could help with exercise-induced asthma, too, notes Dr. Casciari. "Caffeine is a mild bronchodilator," he explains — meaning it helps increase the surface area of the lung's bronchi and bronchioles, making it easier to breathe.

Your best bet to reducing your coughing after running, though, is to start from the beginning: Start with a symptom journal that you can then bring to your own doctor, recommends Dr. Casciari. "Get a notebook and write down certain things," such as, "Number one: When do the problems occur? Number two: How long does it last? Number three: What makes it worse? What makes it better? That way, you can go to the doctor armed with information," he explains.

Turns out, I don't have exercise-induced asthma, but I do tend to get track hack. After following Dr. Casciari's advice and wearing my neck gaiter over my mouth during this weekend's 10-miler, though, I can tell you I coughed far less (and for far less time) upon returning home. That's a little victory I'll definitely celebrate.